Revolver type developing device for an image forming apparatus

Abstract

A revolver type developing device for an image forming apparatus. A rotary body is mounted on a shaft and has a plurality of developing units mounted thereon. The developing units are arranged around the shaft, and each stores a powdery developer and accommodates a developer transport member for supplying the developer to an image carrier. A drive source rotates the rotary body to bring any one of the developing units to a developing position where the developing unit faces the image carrier. A one-way transmission mechanism is located on a drive transmission path extending from the drive source to the rotary body for preventing a drive force from being imparted from the rotary body to the drive source. When the rotary body tends to rotate or vibrate due to an external force or vibration, the rotation or vibration is prevented from reaching the drive source.

What is claimed is: 
     
       1. A revolver type developing device for an image forming apparatus, comprising: a rotary body rotatable about a shaft;   a plurality of developing units mounted on said rotary body around said shaft and each storing a powdery developer and accommodating a developer transport member for supplying said powdery developer to an image carrier;   a drive source for rotating said rotary body to bring any one of said plurality of developing units to a developing position where the developing unit faces the image carrier; and   a one-way transmission mechanism located on a drive transmission path extending from said drive source to said rotary body for preventing a drive force from being imparted from said rotary body to said drive source.   
     
     
       2. A device as claimed in claim 1, wherein said one-way transmission mechanism comprises a worm and a worm wheel meshing with said worm. 
     
     
       3. A device as claimed in claim 2, wherein said worm is operatively connected to said drive source.